The invention relates to a torque-transmitting apparatus with a fluid-operated torque coupler such as, e.g., a fluid coupling or a hydrodynamic torque converter, with at least one housing that can be connected to a driving shaft of a prime mover. The housing contains at least one impeller pump receiving torque from the housing and a turbine that is connected to the input shaft, such as a transmission shaft, of a power train to be driven. Also, if applicable, the housing contains at least one stator arranged between the pump and the turbine. Further, at least one damper is arranged in the power flow between the turbine and a rotary output element of the device. The damper has an input member constrained to rotate together with the turbine and an output member connected to the rotary output element. The input member and the output member are rotatable relative to each other at least against the opposition of a restoring force furnished by energy-storing devices arranged between them.
Torque-transmitting apparatuses of this kind have been proposed, e.g., in DE-OS 195 14 411. To allow rotational displacement of the input and output members relative to each other, it is customary for torque-transmitting apparatuses of this kind to be equipped with a hub that has a toothed internal profile establishing a positive engagement with the transmission shaft and also a toothed external profile which mates with a further component, normally a further hub that carries the turbine and has a toothed internal profile, with play between the flanks of the mating teeth. When a lockup clutch is added that is activated by an axial control piston, there needs to be a corresponding axial space to allow for the axial travel of the hub containing the two toothed profiles. The manufacture of hubs of this kind is complex and therefore expensive. Furthermore, due to the required axial dimension, longer transmission shafts will be needed. Added to this is the difficulty of connecting bulky hub components with the filigreed construction of the turbine shell. Also, dampers that extend far in the radial direction have a tendency to wobble. If in an attempt to solve these problems, the damper is axially docked to the turbine along two or more perimeters of different radii, this will cause undesirable stresses and frictional losses in the damper.